I’ll be the first to tell you that I like to “veg out” during summer but at a certain point, I have to get my brain going again. There are many ways we can jog our brain while we’re out of school; we can pick up a good novel to read, or hit the textbooks and study. With the rise of smartphones, mobile apps and games can also help our brains stay in shape during the hot days of summer. Here’s some of my favorite apps on Android, iOS and Windows Phone for keeping that thinking-muscle in shape!

A man surfing, a boy waving, a beach, a red-haired woman. It’s up to you to figure out what the four images have in common. What’s the Word is a simple game; the player is given four pictures and the object is to try to guess what the word is. It’s addictive and deceptively difficult. There are a lot of games like this on all platforms and they’re usually free, a win-win for everybody!

The object of the game is to find the most words on the game board within two minutes, while competing against thousands of players around the world. One of the coolest aspects of Wordament is that it can connect to your Xbox Live account and get you achievements for your gamerscore. It’s also free!

I still play this because I love Scrabble-like games. If you haven’t played it before, it’s easy to pick up. You’re given a set of seven random letters and you’re supposed to create words with them on the board. You can stick letters onto your opponent’s words and create new words that way too. It’s incredibly easy to jump into, but can be challenging depending on which friend you’re playing. English majors have the leg up here! Note: there’s no free free version for Windows Phone users, instead they have to pay $2.99 for the game, which at least removes ads.

This award-winning game is a physics-based game that tasks the player to build bridges and other objects to complete each puzzling level. You build by using the little creatures made of goo, stick them together and make them into whatever you wish! Unlike the other titles on this list, World of Goo is more of a full-sized game with lots of levels and rich 3D graphics. All of this comes at a cost. The game is currently $4.99 on iTunes and Google Play, but there is a demo version for Android here.

Flow Free is a simple game of connect-the-dots, however the trick is you cannot have one line intersect the other. It’s fairly simple at first but as the levels continue, it becomes truly challenging. Pick it up on whatever device you have as its simplistic design acts as relaxing game to play anywhere.

What are your favorite brain games and apps? Let us know in the comments below!